Normalizing the response of a fluorescence instrument using spectral response

ABSTRACT

A method to normalize at least one of a population of subordinate clinical diagnostic analyzer to a master clinical diagnostic analyzer such that an assay result from a subordinate clinical diagnostic analyzer can be converted to the equivalent result of the master clinical diagnostic analyzer by using a simple multiplicative factor when the assay executed on each analyzer uses a common fluorescently labeled dye. Also a method to re-normalize a subordinate clinical diagnostic analyzer assay result to a master clinical diagnostic analyzer assay result by using a simple multiplicative factor when the assay executed on the subordinate clinical diagnostic analyzer uses a different fluorescently labeled dye than the assay executed on the master clinical diagnostic analyzer.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims priority under applicable portions of 35 U.S.C. §119 to U.S. Patent Application Ser. No. 62/052,132, filed Sep. 18, 2014, and entitled: FLUORESCENT STANDARDS FOR AUTOMATIC RECALIBRATION, the entire contents of which are incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates generally to a method of calibrating diagnostic analyzers using fluorometry as a measurement mechanism.

BACKGROUND OF THE INVENTION

The present invention pertains to at least one clinical diagnostic analyzer conducting an immunoassay employing a fluorescence label. Typically, a fluorescence label is bound to antibodies or antigens having an affinity for the analyte of interest. The unknown analyte in the sample then binds with the labeled antibodies or antigens which are usually immobilized to a substrate. The unbound, labeled antibodies or antigens are subsequently washed away, and the concentration of bound, labeled antibodies or antigens is measured using fluorometry.

Fluorometry is the measurement of fluorescence. Fluorescence is the molecular adsorption of light energy at one wavelength and its nearly instantaneous re-emission at another, usually longer, wavelength. The instrument used to measure fluorescence is called a fluorometer. A fluorometer generates the wavelength of light required to excite the analyte of interest and then it measures the intensity of the resulting emitted light. The amount or quantity of emitted light is frequently proportional to the concentration of the analyte being measured. When employed in clinical diagnostic analyzers fluorometry provides extraordinary sensitivity, high specificity, simplicity, and low cost as compared to other analytical techniques.

To insure the quality control of results from fluorometers, some form of stable reference standard is employed such as National Institute of Standards and Technology (NIST) SRM (Standard Reference Material) 2944 glass. SRM 2944 is a cuvette-shaped, bismuth-ion-doped glass, recommended for use for relative spectral correction of emission and day-to-day performance verification of steady-state fluorescence spectrometers. Further information regarding SRM 2944 is described by Paul C. DeRose; Melody V. Smith; Jeffrey R. Anderson; Gary W. Kramer in the Journal of Luminescence, Volume 141, pp. 9-14, entitled “Characterization of Standard Reference Material 2944, Bi-Ion-Doped Glass, Spectral Correction Standard for Red Fluorescence” which is hereby incorporated by reference in its entirety.

One problem presented by fluorometers is that variations in the manufacture of clinical diagnostic analyzers are such that for a given fluorescence label; the population of clinical diagnostic analyzers will not provide the same analytical result for a specific quantity of analyte in a sample. These manufacturing variations result from differences in excitation light spectra from the laser diode, variances in transmission characteristics of optical filters, etc. Hence, to account for these variations and to provide accurate results each individual clinical diagnostic analyzer must be calibrated.

Another problem presented by fluorometers is that the introduction of a new fluorescence label having differing absorption and emission spectra will require a total re-calibration of the entire clinical diagnostic analyzer population.

SUMMARY OF THE INVENTION

One object of the present invention is to enable a population of clinical diagnostic analyzers or instruments to be normalized to a specific master clinical diagnostic analyzer or instrument such that the response of any subordinate clinical diagnostic analyzer or instrument in the population to a sample having a specific amount of analyte is substantially the same as the response of the master clinical diagnostic analyzer or instrument to that sample after an initial factory calibration.

Another object of the present invention is allow the introduction of a new fluorescence label having a different adsorption and emission spectrum as compared to a prior fluorescence label such that the re-calibration and re-normalization of the entire population of clinical diagnostic analyzers to the master clinical diagnostic analyzer depends only upon the absorption and emission spectra of the new fluorescence label. Total re-calibration of the population of clinical diagnostic analyzers is not required.

The foregoing and further objects of the invention are accomplished according to one aspect of the invention that provides a method of normalizing a first diagnostic result of a subordinate clinical diagnostic analyzer to a second diagnostic result of a master clinical diagnostic analyzer comprising the steps of obtaining a normalized excitation intensity spectrum of the master clinical diagnostic analyzer, obtaining a normalized excitation intensity spectrum of the subordinate clinical diagnostic analyzer, obtaining a normalized responsivity intensity spectrum of the master clinical diagnostic analyzer, obtaining a normalized responsivity intensity spectrum of the subordinate clinical diagnostic analyzer, obtaining a normalized excitation/emission spectrum of a solid inorganic photostable fluorophore calibration target, reading the solid inorganic photostable fluorophore calibration target in the master clinical diagnostic analyzer thereby obtaining a first response value, reading the solid inorganic photostable fluorophore calibration target in the subordinate clinical diagnostic analyzer thereby obtaining a second response value, determining the gain ratio of the master clinical diagnostic analyzer to the subordinate clinical diagnostic analyzer based upon the two above obtained response values, determining a multiplicative normalization factor between a normalized subordinate clinical diagnostic analyzer and the master clinical diagnostic analyzer, determining the relative adsorption/emission spectrum of a first fluorescently labeled dye whereas the first fluorescently labeled dye is a diagnostic assay component, obtaining a first diagnostic result from a specific patient specimen or sample incorporating the first fluorescently labeled dye using the normalized subordinate clinical diagnostic analyzer, and multiplying the first diagnostic result by the multiplicative normalization factor to obtain a second diagnostic result whereas the second diagnostic result is a normalized approximation to a diagnostic result which would be obtained by analyzing the specific patient specimen or sample on the master clinical diagnostic analyzer.

Still another aspect of the invention provides a method to re-normalize a subordinate clinical diagnostic analyzer assay result as compared to a master clinical diagnostic analyzer assay result comprising the steps of normalizing the subordinate clinical diagnostic analyzer as above, obtaining a relative adsorption/intensity spectrum of a second fluorescently labeled dye whereas the second fluorescently labeled dye is a diagnostic assay component, determining a re-normalization multiplicative factor between a subordinate clinical diagnostic analyzer and a master clinical diagnostic analyzer, obtaining a first diagnostic result from a specific patient specimen or sample incorporating the second fluorescently labeled dye using the normalized subordinate clinical diagnostic analyzer, and multiplying the first diagnostic result by the re-normalization factor to obtain a second diagnostic result whereas the second diagnostic result is a normalized approximation to a diagnostic result which would be obtained by analyzing the specific patient specimen or sample on the master clinical diagnostic analyzer.

Further objects, features and advantages of the present invention will be apparent to those skilled in the art from detailed consideration of the preferred embodiments that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the chemistry associated with an immunoassay usually contained in an analytic slide (not shown).

FIG. 2 is a schematic diagram of an optical detection system associated with a fluorescence detection analyzer.

FIG. 3 is a graph of the relative adsorption and emission spectrum of Alexa Fluor® 635, a dye commonly used a fluorophore label.

FIG. 4 is a graph of the relative adsorption and emission spectrum of Alexa Fluor® 647, another dye commonly used a fluorophore label.

FIG. 5 is a graph of an example master instrument linear calibration curve.

FIG. 6 is a graph of an example master instrument nonlinear calibration curve.

FIG. 7 is a histogram of the responses to a set of fixed analyte concentration samples or specimens using Alexa Fluor® 647 when subjected to instrument variations.

FIG. 8 is a histogram of the ratio of responses to a set of fixed analyte concentration samples or specimens comparing bismuth-doped phosphor glass and Alexa Fluor® 647 when subjected to instrument variations.

FIG. 9 is a histogram of the ratio of responses to a set of fixed analyte concentration samples or specimens comparing bismuth-doped phosphor glass and Alexa Fluor® 647 when subjected to instrument variations when corrected using instrument normalization.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

While the present invention is described with respect to preferred embodiments as detailed below and shown in the figures, the present invention is limited only by the metes and bounds of the claims that follow.

Fluorometry is chosen for its extraordinary sensitivity, high specificity, simplicity, and low cost as compared to other analytical techniques. Fluorometry is ordinarily 1000-fold more sensitive than absorbance measurements. It is a widely accepted and powerful technique that is used for a variety of environmental, industrial, and biotechnology applications. It is a valuable analytical tool for both quantitative and qualitative analysis. However, fluorometry requires a stable fluorescence standard to insure that the clinical diagnostic analyzers remain normalized and in calibration. Organic fluorophores, especially those in liquid form, are not well suited for use in normalizing analyzers in a factory setting because they photobleach, have limited shelf life, are prone to carryover problems, and are difficult to dose. A solid inorganic photostable fluorophore would not have the above problems, but there are only a limited number of these materials available.

In conjunction with a preferred embodiment of the present inventive method, a device has been designed using a National Institute of Standards and Technology (NIST) developed material consisting of a phosphate matrix glass doped with bismuth ion such that the glass has fluorescent properties. This material is known as NIST Standard Reference Material (SRM) 2944 glass. The composition of such material is shown in Table A.

TABLE A Composition of NIST SRM 2944 Glass Ingredient Weight % Mole % P₂O₅ 70.52 49.84 CaO 26.20 47.05 Al₂O₃ 3.04 3.00 Bi₂O₃ 0.51 0.11

This device has been designed to overcome the limitations listed above and is used in connection with this inventive method; see copending United States patent application by Freeman III, Heavner, and Oenick entitled “Fluorescence Reference Standard Device” (Attorney Docket No. CDS5170WOPCT) which is hereby incorporated by reference in its entirety. For different wavelength fluorometry a different material other than NIST SRM 2944 would be used, such as other phosphate doped glasses also available from NIST, including SRM 2943, copper doped glass, spectral correction standard for blue fluorescence.

The above described NIST SRM 2944 glass device is a preferred solid inorganic photostable fluorophore used in the inventive method described herein to normalize a population of subordinate clinical diagnostic analyzers to a master clinical diagnostic analyzer. Using the excitation and emission spectrums of the NIST SRM 2944 glass, the excitation and emission spectrums of the fluorescence label employed in the combination fluorescently labeled label antibody reagent, and the measured excitation and responsivity spectrums inherent in the optical detection systems of the master and subordinate clinical diagnostic analyzers, normalization of subordinate analyzers to the master analyzer is performed at the factory. Using samples or specimens of known analyte concentrations, a standard calibration can likewise be performed at the factory. And furthermore, should it be required or desirable to change the label in the combination fluorescence label antibody reagent, this can be accomplished in the field using only the excitation and emission spectrums of the new fluorescence label.

One advantage of the inventive method is that by using solid inorganic photostable fluorophore, such as the preferred NIST SRM 2944 glass, as a reference material, a population of subordinate clinical diagnostic analyzers can be normalized to one master clinical diagnostic analyzer such that after a factory normalization and calibration the subordinate clinical diagnostic analyzers will have substantially the same response to a sample or specimen containing a fixed amount of analyte as would the master clinical diagnostic analyzer.

Furthermore, should it become necessary or desirable to change the fluorescence label in the combination fluorescence label antibody reagent, then the population of subordinate clinical diagnostic analyzers can be re-normalized (and retain the original factory calibration) by a simple procedure not requiring a total recalibration in the field.

For a general understanding of the disclosed methods, reference is made to the drawings. In the drawings, like reference numerals have been used to designate identical elements. In describing the disclosed methods, the following term(s) have been used in the description.

The term “ξ” (the Greek letter xi) or “emission” refers to one or more wavelengths of light generated as a result of fluorescence, specifically when “ξ” is used in an equation it stands for emission wavelength.

The term “responsivity” refers to the normalized output of an optical intensity measuring system as a function of a specific wavelength of light being input to that system.

The term “χ” (the Greek letter chi) or “excitation” refers to one or more wavelengths of light generated to be used as a source to radiate a fluorescence complex, specifically when “χ” is used in an equation it stands for excitation wavelength.

The term “absorbance” refers to the normalized extinction coefficient of a fluorescent dye.

The term “spectral distribution” or “shape function” refers to the relative intensity of an excitation or emission light beam as a function of wavelength.

The term “clinical diagnostic analyzer,” “diagnostic analyzer,” and “instrument” are taken to mean devices that accept a patient sample or specimen, analyze the sample or specimen for a specific analyte, and report the result of that analysis. These terms are meant to encompass clinical chemistry analyzers, immunohematology analyzers, lateral flow device readers, and the like.

The term “normalize” refers to the inventive method applied to two clinical diagnostic analyzers or instruments, a master instrument “A” and a subordinate instrument “B”, such that the response of “B” to a specific sample or specimen containing a certain concentration of analyte can be converted to the response of “A” to the same sample or specimen by using a multiplicative factor when the assay method employed by the analyzers uses a common fluorescently labeled dyes.

The term “re-normalize” refers to the inventive method applied to two clinical diagnostic analyzers or instruments, a master instrument “A” and a subordinate instrument “B”, such that the response of “B” to a specific sample or specimen containing a certain concentration of analyte can be converted to the response of “A” to the same sample or specimen by using a multiplicative factor when the assay method employed by the analyzers uses differing fluorescently labeled dyes.

The terms “Alexa Fluor® 635” and “Alexa Fluor® 647” refer to preferred organic fluorophores that can be used as fluorescent tags. These materials are made by INVITRO-GEN™. For example, the adsorption/emission spectrum of “Alexa Fluor® 635” is shown in FIG. 3 and “Alexa Fluor® 647” has a absorption maximum at 650 nm and an emission maximum at 671 nm as shown in FIG. 4. “Alexa Fluor® 635” is sometimes abbreviated as “AF 635” and “Alexa Fluor® 647” is sometimes abbreviated as “AF 647”.

In FIG. 1 a combination fluorescently labeled antibody reagent 101 is added to a target analyte 102 (an antigen in this specific example) in the sample or specimen wherein the combination fluorescence label antibody reagent 101 binds to the analyte forming an antibody-analyte complex 103. Unbound combination fluorescence label antibody reagent 101 is subsequently removed. The bound antibody-analyte complex 103 is then exposed to an excitation light of specific wavelength causing a fluorescence emission proportional to the amount of analyte present to be generated shortly thereafter.

In FIG. 2 the bound antibody-analyte complex 103 is captured in a very thin, well defined volume (normally some form of analysis slide, not shown) and presented at the sample plane 201. Excitation light is generated by the light emitting diode (LED) source 208 then collimated by condenser system lenses 210, filtered by the excitation filer 207, shaped by the excitation aperture 206 and the projection lens 211, redirected by a dichroic mirror 203, and then passed through an objective lens 202 that acts to converge the excitation light rays down to an area appropriate for the very thin, well defined volume. The excitation system components contained in the dashed rectangle are called the excitation arm 209 of the optical detection system. Any captured and tagged analyte in that volume fluoresces, and a portion of that emission is intercepted by the objective lens 202, passed through the dichroic mirror 203, further passed through at least one band pass filter 204, through a detector lens 212, and finally through a detection aperture 213. The emission light making it through the detection aperture 213 strikes the photodetector 205 and generates an electric current which is amplified into a usable signal.

At the photodetector 205, the excitation arm 209 of the optical detection system delivers a photon flux (some number of photons per second) with some spectral distribution (i.e., some mix of wavelengths). This can be described by

Φ(χ)=φ·S(χ)  (1)

where φ is a scalar (units=photons/second) and S(χ) is a unitless shape function where the maximum value of S(χ) is unity. The magnitude of is determined by the output of the LED source 208, the attenuation properties of the filters 207 and, the attenuation properties of the lenses 210, 211, and 202, the reflective properties of the dichroic mirror 203, and the position tolerances of the optical elements. The characteristics of S(χ) are determined by the spectral properties of the LED source 208 and the transmission spectrum of the filter 207 and the reflective characteristics of the dichroic mirror 203.

If the NIST SRM 2944 glass is exposed to the photon flux Φ(χ) of equation (1), a composite emission curve will be obtained that can be approximated by summation over small increments of Δχ, i.e., the value of S(χ) at a particular χ times the normalized emission curve EC_(glass) at that wavelength. That is,

Σ_(χ) S(χ)·ECglass(χ,ξ)  (2)

The fluorescence photo flux Φ(ξ) emitted by the glass can be written as

Φ(

ξ)=ψ·φ·Σ_(ξχ) S(ξχ)·ECglass(χ,ξ)  (3)

where ψ is a scalar that is characteristic of the output of the NIST SRM 2944 glass.

The electrical signal (current) that is generated at the detector at a particular emission wavelength χ can be described by

E(ξ)=Φ(ξ)·G·S _(R)(ξ)  (4)

where G is a constant and S_(R)(ξ) is a shape function such that the maximum value of S_(R) (ξ) is unity. The magnitude of G is determined by the collection efficiency of the optics 202 and 212, the transmission efficiency of the dichroic mirror 203 and emission filters 204. The characteristics of S_(R)(ξ) are determined by the spectral characteristics of the dichroic mirror 203, emission filters 204 and the spectral characteristics of the detector (photodiode) 205. The total electrical signal generated is

E=Σ _(ξ) G·S _(R)(ξ)·Φ(ξ)=G·Σ _(ξ) S _(R)(ξ)·[ψ·φ·Σ_(χ) S(χ)·ECglass(χ,ξ)]  (5)

or,

E=G·ψ·φ·Σ _(ξ) S _(R)(ξ)·[Σ_(χ) S(χ)·ECglass(χ,ξ)]  (6)

Suppose there is a master instrument “A” and a subordinate instrument “B” where Instrument “B” is to be normalized to instrument “A.” Using eqn. (6), the ratio of the signals (E_(A) and E_(B)) given by the two instruments in response to being presented with an identical NIST SRM 2944 glass target can be written as

$\begin{matrix} {\mspace{79mu} {{\frac{E_{A}}{E_{B}} = \left\{ \frac{{G_{A} \cdot \psi \cdot \phi_{A} \cdot \Sigma_{\chi}}{{S_{RA}(\chi)} \cdot \left\lbrack {\Sigma_{\xi}{{S_{A}(\xi)} \cdot {{ECglass}\left( {\xi,\chi} \right)}}} \right\rbrack}}{{G_{B} \cdot \psi \cdot \phi_{B} \cdot \Sigma_{\chi}}{{S_{RB}(\chi)} \cdot \left\lbrack {\Sigma_{\xi}{{S_{B}(\xi)} \cdot {{ECglass}\left( {\xi,\chi} \right)}}} \right\rbrack}} \right\}}\mspace{20mu} {{or},}}} & (7) \\ {G_{R} = {\left( \frac{G_{A} \cdot \phi_{A}}{G_{B} \cdot \phi_{B}} \right) = {\left( \frac{E_{A}}{E_{B}} \right) \cdot \left\{ \frac{\Sigma_{\chi}{{S_{RB}(\chi)} \cdot \left\lbrack {\Sigma_{\xi}{{S_{B}(\xi)} \cdot {{ECglass}\left( {\xi,\chi} \right)}}} \right\rbrack}}{\Sigma_{\chi}{{S_{RA}(\chi)} \cdot \left\lbrack {\Sigma_{\xi}{{S_{A}(\xi)} \cdot {{ECglass}\left( {\xi,\chi} \right)}}} \right\rbrack}} \right\}}}} & (8) \end{matrix}$

where G_(R) is called the gain ratio. The responsivities of both instrument A and instrument B (S_(RA)(ξ) and S_(RB)(ξ), respectively) can be measured by presenting a constant intensity variable wavelength light source to each instrument in turn, sweeping the source through the range of wavelengths in the transmission band of the emission filters 204 and the dichroic mirror 203 while monitoring the signal generated by the respective instrument, then normalizing that signal by the maximum value obtained during that sweep. The emission spectra of both instruments, S_(A)(χ) and S_(Z)(χ), are easily measured by a spectrometer.

Consider now the case of a fluorescent label, specifically Alexa Fluor® 647, where in FIG. 3 the solid excitation curve 301 is designated by S_(DYE)(ξ). The equivalent digital values for S_(DYE)(χ) are presented in Table 4. Also for Alexa Fluor® 647, in FIG. 3 the dashed emission curve 302 is designated by S_(DYE)(ξ). The equivalent digital values for S_(DYE)(ξ) are presented in Table 5.

The photon flux Φ_(DYE)(ξ) emitted by the fluorescent label (dye) can be written as

Φ_(DYE)(ξ)=φ_(DYE)·φ·[Σ_(ξ) S(ξ)·S _(DYE)(ξ)]·S _(DYE)(ξ)  (9)

where φ_(DYE) is a scalar that is characteristic of the output of the fluorescence label (dye).

Rewriting eqn. (6) in terms of the fluorescence label (dye) gives

$\begin{matrix} {\mspace{79mu} {{E = {G \cdot \phi_{DYE} \cdot \phi \cdot \left\lbrack {\Sigma_{\xi}{{S_{R}(\xi)} \cdot \left\lbrack {\Sigma_{\chi}{{S(\chi)} \cdot {S_{DYE}(\chi)}}} \right\rbrack \cdot {S_{DYE}(\chi)}}} \right\rbrack}}\mspace{20mu} {{and},}}} & (10) \\ {{\frac{E_{A}}{E_{B}} = \left\{ \frac{{G_{A} \cdot \phi_{DYE} \cdot \phi_{A} \cdot \Sigma_{\xi}}{{S_{RA}(\xi)} \cdot \left\lbrack {\Sigma_{\chi}{{S_{A}(\chi)} \cdot {S_{DYE}(\chi)}}} \right\rbrack \cdot {S_{DYE}(\xi)}}}{{G_{B} \cdot \phi_{DYE} \cdot \phi_{B} \cdot \Sigma_{\xi}}{{S_{RB}(\xi)} \cdot \left\lbrack {\Sigma_{\chi}{{S_{B}(\chi)} \cdot {S_{DYE}(\chi)}}} \right\rbrack \cdot {S_{DYE}(\xi)}}} \right\}}\mspace{79mu} {{or},}} & (11) \\ {\mspace{79mu} {E_{A} = {{E_{B} \cdot G_{R}}\left\{ \frac{{\cdot \Sigma_{\chi}}{{S_{RA}(\xi)} \cdot \left\lbrack {\Sigma_{\chi}{{S_{A}(\chi)} \cdot {S_{DYE}(\chi)}}} \right\rbrack \cdot {S_{DYE}(\xi)}}}{\Sigma_{\chi}{{S_{RB}(\xi)} \cdot \left\lbrack {\Sigma_{\xi\chi}{{S_{B}(\chi)} \cdot {S_{DYE}(\chi)}}} \right\rbrack \cdot {S_{DYE}(\xi)}}} \right\}}}} & (12) \end{matrix}$

Therefore, we can transform the response E_(S) from analyzer “B” to the response E_(A) that would be seen by the master analyzer “A” using eqn. (12).

This allows introduction of new fluorescence labels (dyes) to subordinate field instruments and allowing those subordinate field instruments to be re-normalized to a master analyzer “A” by simply providing the absorption and emission spectrum of the new fluorescence label (dye) and using eqn. (12).

In summary, the following is conducted in the factory for each subordinate instrument:

-   -   Measure S_(Z)(χ) and store this information on the instrument.     -   Measure S_(RZ)(ξ)) and store this information on the instrument.     -   The Gain Ratio of each instrument is determined by scanning the         NIST SRN 2944 calibration slide as a target, and then applying         eqn. (8).

Exemplary Example of Factory Normalization

In this example, Analyzer AP106 is selected as the master instrument and Analyzer AP115 is selected as the subordinate instrument. The goal of this factory normalization is to determine the relationship between the two analyzers with respect to their individual responses to the same sample. This means that a response to a particular sample for the subordinate instrument can be converted to the response of the master instrument by multiplying the response of the subordinate instrument by the gain ratio and the remainder of the eqn. (12) to the right of G_(R) (as derived above and to be determined for this example below). The initial data gathering steps can be listed as follows:

-   -   1. Obtain the normalized excitation intensity spectrum of AP106         (see Table 1 for the digital spectrophotometric data).     -   2. Obtain the normalized excitation intensity spectrum of AP115         (see Table 1 for the digital spectrophotometric data).     -   3. Obtain the normalized responsivity intensity spectrum of         AP106 (see Table 2 for the digital spectrophotometric data).     -   4. Obtain the normalized responsivity intensity spectrum of         AP115 (see Table 2 for the digital spectrophotometric data).     -   5. Obtain the normalized excitation/emission spectrum of NIST         SRM 2944 glass (see Table 3A, 3B, and 3C for the digital         spectrophotometric data).     -   6. Read the NIST SRM 2944 glass as a target in AP106 obtaining         the response value for E_(A) of 2181.705 relative fluorescence         units (RFU).     -   7. Read the NIST SRM 2944 glass as a target in AP115 obtaining         the response value for E_(Z) of 2035.274 RFU.     -   8. Calculate the Gain ratio of AP106 to AP115 using eqn. (8)         where the numerator in brackets has the value 123.9541 and the         denominator in brackets has the value 126.4753 with a result as         follows:

$G_{R} = {{\left( \frac{2181.705}{2035.274} \right)*\left( \frac{123.9541}{126.4763} \right)} = 1.0506}$

-   -   -   Note that the ratio (123.9541/126.4763) expresses the             difference in signal between the two instruments based on             spectral differences. Whereas the gain ratio G_(R) expresses             differences due to non-spectral differences (e.g., one             instrument may have a slightly brighter illumination LED or             somewhat more efficient receiver optics).

    -   9. Obtain the relative absorption spectrum of the fluorescent         label (dye) used in the analysis. In this case Alexa Fluor® 647         is being used and the associated digital spectrophotometric data         is presented in Table 4.

    -   10. Obtain the relative emission intensity of the fluorescent         label (dye) used in the analysis. In this case Alexa Fluor® 647         is being used and the associated digital spectrophotometric data         is presented in Table 5.

    -   11. Using eqn. (12), the normalization factor between AP115         responses and AP106 responses can be determined as follows where         the numerator in eqn. (12) is 122.1005 and the denominator in         eqn. (12) is 117.6860:

$\frac{E_{A}}{E_{Z}} = {{(1.0505)*\left( \frac{117.6860}{122.1005} \right)} = 1.0126}$

-   -   -   That is, to convert a response from AP115 to a response             normalized to AP106 when making measurements with Alexa             Fluor® 647, we must multiply the AP115 responses by 1.0126.

Exemplary Example of Field Re-Normalization

In this example, subordinate instrument AP115 has been previously normalized to master instrument AP106 and it is desired to introduce a new fluorescent label (dye). The prior analysis allows introduction of new fluorescent labels (dyes) to subordinate field instruments and allowing those subordinate field instruments to normalize to the master analyzer by simply providing the absorption and emission spectrum of the new dye and using eqn. (12) above. The method is outlined as follows:

-   -   1. Obtain the relative absorption spectrum of the fluorescent         label (dye) used in the analysis. In this case Alexa Fluor® 635         is being used and the associated digital spectrophotometric data         is presented in Table 6.     -   2. Obtain the relative emission intensity of the fluorescent         label (dye) used in the analysis. In this case Alexa Fluor® 635         is being used and the associated digital spectrophotometric data         is presented in Table 7.     -   3. Using eqn. (12), the normalization factor between AP115         responses and AP106 responses can be determined as follows where         the numerator in eqn. (12) is 44.02245 and the denominator in         eqn. (12) is 45.2193:

$\frac{E_{A}}{E_{Z}} = {{(1.0506)*\left( \frac{44.02245}{45.2194} \right)} = 1.0274}$

-   -   -   That is, to convert a signal from AP115 to a signal             normalized to AP106 when making measurements with Alexa             Fluor® 635 as opposed to Alexa Fluor® 647, we must multiply             the AP115 signals by 1.01274. Note that the Gain Ratio is             not dependent upon the fluorescent label (dye) and remains             constant.

In practice, when a new fluorescence label (dye) is introduced to a subordinate field instrument, the quantity

Σ_(χ) S _(RB)(ξ)·[Σ_(ξχ) S _(B)(χ)·S _(DYE)(χ)]·S _(DYE)(ξ)

-   -   will be provided to that instrument along with

S _(DYE)(ξ) and S _(DYE)(χ)

-   -   so that it is capable of running assays that make use of that         new fluorescence label (dye).

Exemplary Example of Factory Linear Calibration

In this example, a standard calibration procedure will be conducted with samples or specimens of known analyte concentration. The procedure will utilize 10 samples having known analyte concentrations of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 ng/mL. The master instrument responses were observed to be 1.15, 1.90, 3.10, 3.90, 5.05, 5.95, 7.30, 7.90, 8.90, and 10.20. This data is presented in Table 8. For fluorometry, the amount of emitted light is frequently proportional to amount of analyte present in the sample or specimen; hence, a linear calibration curve is usually employed. Here the known concentration values, which are known without error, are used as the predictor variable and the master instrument responses, containing measurement error, are used as the response variable. This situation is known to satisfy the requirement for using ordinary least squares (OLS) regression. The data of Table 8 and the fitted regression line are shown in FIG. 5. The data points 501 of Table 8 and the fitted OLS regression line (shown as a solid black line) 502 indicate a close correlation for the master instrument.

For the master instrument, the instrument response to a sample or specimen (as indicated by a y-axis value) is traced back to the right horizontally to the fitted linear calibration line and then traced vertically to the x-axis to obtain the estimate of the analyte concentration in the sample or specimen. For example, in FIG. 5, if the master instrument response to a sample or specimen is 5, then tracing to the right, the horizontal line intercepts the linear calibration line and tracing down a value of approximately 5 on the x-axis is obtained.

For the subordinate instruments, subordinate instrument response to a sample or specimen is multiplied by the Gain Ratio and everything to the right of E_(Z) in eqn. (1) such that the resulting response can be used just as if it were obtained from the master instrument to obtain an estimate of the analyte concentration in the sample or specimen. For this specific case, the subordinate instrument would produce a response of 4 and subsequently that response would be multiplied by the gain factor of 1.25 to yield an equivalent master instrument response of 5. Also using the master calibration curve produces an estimated analyte concentration of approximately 5.

Exemplary Example of Field Linear Re-Calibration

In this example, a new fluorescent label (dye) has been introduced into the analysis chemistry and the subordinate instruments in the field have been re-normalized. For this situation there are two methods that can be used to obtain appropriate estimates of the analyte concentration in the sample or specimen as follows:

-   -   1. The subordinate instrument response can be multiplied by the         normalization factor and the old factory calibration curve can         be used. In FIG. 5, for a subordinate instrument response of 4         and a normalization factor of 1.25, this is represented by the         up arrow indicating that 4*1.25=5 is the equivalent master         instrument response. Starting a 5 on the y-axis and tracing         right to the master linear calibration line 502 and then down to         the x-axis produces an estimate of 5.     -   2. Alternatively, a new linear calibration 503 curve can be         constructed by multiplying the slope of the old linear         calibration curve 502 by the inverse of the normalization         factor. The new calibration curve 503 would then, as in in FIG.         5, have a slope of 1.005*(1/1.25)=0.804. The estimate of the         analyte concentration in the sample or specimen would then be         obtained by starting on the y-axis at the subordinate instrument         response (4) then tracing to the right until the new linear         calibration curve is encountered and then moving down to the         x-axis. It is clear from FIG. 5 that this procedure or the         procedure 1 above that both result in the same analyte         concentration estimates.

Exemplary Example of Factory Non-Linear Calibration

In this example, the amount of emitted light is not proportional to amount of analyte present in the sample or specimen; hence, a linear calibration curve cannot be used. In a manner similar to the linear calibration example, a series of 10 samples or specimens of known analyte concentrations is prepared and a non-linear sigmoidal function 601 is fitted to the data points 602. Hence, for the master instrument, a y-axis response is converted into an estimate of analyte concentration, by starting at the y-axis value, tracing right until the calibration curve is encountered and then tracing down to the x-axis to obtain the analyte concentration estimate.

Exemplary Example of Field Non-Linear Re-Calibration

In this example, FIG. 6 shows a non-linear (s-shaped) calibration curve 601. Assuming that the normalization factor is 1.25 between the master and subordinate instruments, a subordinate instrument response of 4 would generate an equivalent master instrument response of (4*1.25)=5 which would produce an estimated analyte concentration of approximately 5½. Unlike the linear calibration case, the slope of the non-linear calibration curve cannot be easily adjusted such that the raw subordinate instrument response can be used. Here it is necessary to multiply the subordinate instrument response by the normalization factor to obtain the equivalent master instrument response and then use the master instrument calibration curve.

Simulation Test of Normalization Factor Effectiveness

To test the effectiveness of the normalization process, an initial Monte Carlo simulation was conducted where 10,000 simulated fluorescence analyzers were presented with a fixed amount of Alexa Fluor® 647 (AF 647) fluorescence label (dye) or a fixed amount of bismuth-doped glass as used in the NIST SRM 2944 standard. Sources of variation were as follows:

-   -   1. Incubation temperature was allowed to vary between 36° C. and         38° C.     -   2. The bandpass characteristics of 3 optical filters in the         detection arm of the optical detection system were allowed to         vary (according the manufacturers specification)     -   3. The excitation wavelength was allowed to vary between 630 nm         and 636 nm.

After 10,000 simulated analyzers were configured according to the above, the model generated the statistics of a variety of responses. FIG. 7 shows the resulting histogram 701 of responses to simulated samples using AF 647 dye. There is about a +/−25% range in the population response. FIG. 8 shows the population of ratios of each individual analyzer's response to AF 647 and the NIST SRM 2944 standard. The resulting histogram of responses 801 shows a spread of about +/−20%. Clearly, the raw response of the NIST SRM 2944 does a poor job in predicting the response of the instrument to the samples using AF 647. However, if the same analysis is repeated where a normalization factor is employed and measurement noise (error) in the following is allowed:

-   -   1. Noise associated with the analyzer aligning and reading the         calibration slide. A value was used of 0.5% CV that should be         achievable with 4 load and align events each with 4 reads of the         fluorescent label (dye). The alignment process was actually a         fairly significant source of variability.     -   2. Noise associated with the characterization of the analyzer's         excitation and responsivity spectra by factory calibration         instrumentation. It was estimated that each data point had a         0.25% CV imprecision.     -   3. Noise associated with the characterization of the analyzer's         incubation temperature. Noise of one standard deviation was         taken to be 0.067° C. This creates an error because of the         temperature sensitivity differences between the NIST SRM 2944         glass (˜−0.25% per ° C.) and the AF 647 fluorescent label (dye)         (˜−1.2% per ° C.).

FIG. 9 contains the resulting histogram of errors 901 which indicates that the overall analyte estimation error has been reduced to about a range of +/−1%.

It will be apparent to those skilled in the art that various modifications and variations can be made to the article of manufacture disclosed herein. Thus, it is intended that the present invention cover such modifications and variations, provided they come within the scope of the appended claims and their equivalents.

The disclosure of all publications cited above is expressly incorporated herein by reference in their entireties to the same extent as if each were incorporated by reference individually.

TABLE 1 Normalized Excitation Intensity of Analyzers AP106 and AP115 Wavelength Normalized Excitation Normalized Excitation (nm) Intensity AP106 Intensity AP115 610 0.002 0.001 611 0.001 0 612 0 0.002 613 0 0.001 614 0 0.002 615 0.002 0.002 616 0.002 0.003 617 0.002 0.002 618 0.001 0.002 619 0.002 0.004 620 0.002 0.006 621 0.002 0.003 622 0.003 0.006 623 0.002 0.003 624 0.002 0.006 625 0.003 0.004 626 0.003 0.004 627 0.003 0.008 628 0.004 0.008 629 0.005 0.01 630 0.007 0.01 631 0.018 0.015 632 0.107 0.08 633 0.749 0.588 634 1 1 635 1 1 636 0.902 0.888 637 0.783 0.776 638 0.649 0.664 639 0.531 0.547 640 0.422 0.433 641 0.33 0.339 642 0.264 0.287 643 0.201 0.229 644 0.17 0.195 645 0.138 0.169 646 0.106 0.134 647 0.089 0.114 648 0.071 0.094 649 0.052 0.077 650 0.018 0.033 651 0.011 0.023 652 0.014 0.025 653 0.015 0.026 654 0.013 0.026 655 0.016 0.026 656 0.016 0.028 657 0.017 0.029 658 0.016 0.028 659 0.019 0.029 660 0.02 0.033

TABLE 2 Normalized Responsivity of Analyzers AP106 and AP115 Wavelength Normalized Normalized (nm) Responsivity AP106 Responsivity AP115 660 0.000 0 661 0.000 0 662 0.000 0 663 0.000 0 664 0.000 0 665 0.001 0.003 666 0.007 0.033 667 0.076 0.169 668 0.296 0.503 669 0.721 0.857 670 0.931 0.944 671 0.963 0.963 672 0.976 0.974 673 0.984 0.981 674 0.987 0.986 675 0.989 0.987 676 0.987 0.988 677 0.989 0.99 678 0.990 0.991 679 0.990 0.992 680 0.992 0.995 681 0.996 0.999 682 0.999 1 683 1.000 0.999 684 1.000 0.998 685 0.998 0.997 686 0.997 0.996 687 0.995 0.995 688 0.994 0.991 689 0.991 0.977 690 0.973 0.942 691 0.932 0.886 692 0.874 0.825 693 0.813 0.758 694 0.747 0.677 695 0.661 0.577 696 0.557 0.494 697 0.476 0.444 698 0.431 0.361 699 0.348 0.186 700 0.147 0.039 701 0.028 0.007 702 0.006 0.002 703 0.002 0.001 704 0.001 0 705 0.000 0 706 0.000 0 707 0.000 0 708 0.000 0 709 0.000 0 710 0.000 0

TABLE 3A Normalized Excitation/Emission Spectrum of NIST SRM 2944 Glass (Excitation Range of 630 nm to 638 nm) Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Emission λ 630 nm 631 nm 632 nm 633 nm 634 nm 635 nm 636 nm 637 nm 638 nm 660 nm 0.34549 0.33956 0.33023 0.32210 0.31582 0.30802 0.29942 0.29206 0.28678 661 nm 0.35772 0.34993 0.34102 0.33521 0.32440 0.31786 0.31031 0.30331 0.29702 662 nm 0.36896 0.36160 0.35298 0.34501 0.33518 0.33052 0.32255 0.31517 0.30726 663 nm 0.38392 0.37425 0.36760 0.35853 0.34984 0.34257 0.33388 0.32481 0.31928 664 nm 0.39699 0.39019 0.37935 0.37124 0.36228 0.35438 0.34674 0.33794 0.33082 665 nm 0.41212 0.40123 0.39331 0.38280 0.37668 0.36648 0.35845 0.35121 0.34225 666 nm 0.42312 0.41395 0.40579 0.39620 0.38547 0.37763 0.36996 0.36349 0.35335 667 nm 0.43856 0.42995 0.41957 0.41035 0.40103 0.39396 0.38782 0.37574 0.36701 668 nm 0.45547 0.44361 0.43619 0.42548 0.41737 0.40622 0.39897 0.39043 0.38220 669 nm 0.46686 0.45881 0.45030 0.44020 0.43125 0.42149 0.41088 0.40334 0.39448 670 nm 0.48376 0.47254 0.46310 0.45249 0.44417 0.43516 0.42428 0.41614 0.40696 671 nm 0.49900 0.48850 0.47782 0.46725 0.46050 0.44937 0.43894 0.43078 0.42308 672 nm 0.51526 0.50339 0.49342 0.48204 0.47241 0.46424 0.45153 0.44363 0.43545 673 nm 0.52976 0.51942 0.50948 0.49668 0.48821 0.47739 0.46932 0.45703 0.44964 674 nm 0.54523 0.53238 0.52233 0.51327 0.50100 0.49177 0.48550 0.47438 0.46410 675 nm 0.56020 0.55060 0.53721 0.52785 0.51904 0.50735 0.49493 0.48674 0.47747 676 nm 0.57498 0.56199 0.55172 0.53999 0.53040 0.51979 0.51242 0.50051 0.49118 677 nm 0.58950 0.57750 0.56461 0.55440 0.54368 0.53247 0.52302 0.51226 0.50388 678 nm 0.60211 0.58952 0.57800 0.56891 0.55852 0.54858 0.53826 0.52581 0.51567 679 nm 0.61899 0.60799 0.59682 0.58456 0.57233 0.56236 0.55323 0.54233 0.53079 680 nm 0.63571 0.62416 0.61074 0.59914 0.59201 0.57863 0.56691 0.55660 0.54640 681 nm 0.65119 0.63768 0.62549 0.61473 0.60436 0.59340 0.58563 0.57149 0.55993 682 nm 0.66555 0.65240 0.64012 0.63216 0.62131 0.60897 0.59902 0.58693 0.57436 683 nm 0.68193 0.66992 0.65779 0.64809 0.63722 0.62455 0.61273 0.60073 0.59146 684 nm 0.69631 0.68391 0.67507 0.66524 0.65241 0.63948 0.62716 0.61849 0.60849 685 nm 0.71191 0.69806 0.68725 0.67714 0.66511 0.65241 0.64263 0.63119 0.62026 686 nm 0.72485 0.71479 0.70406 0.68995 0.68133 0.66728 0.65735 0.64566 0.63500 687 nm 0.74255 0.72878 0.71670 0.70500 0.69137 0.68162 0.67083 0.65914 0.64813 688 nm 0.75576 0.74375 0.73268 0.72053 0.70923 0.69377 0.68607 0.67391 0.66217 689 nm 0.76864 0.75885 0.74478 0.73313 0.72375 0.70988 0.69743 0.68662 0.67722 690 nm 0.78382 0.76997 0.76045 0.74728 0.73515 0.72335 0.70914 0.69861 0.68906 691 nm 0.79956 0.78754 0.77465 0.76029 0.75030 0.73720 0.72440 0.71331 0.70199 692 nm 0.81396 0.80383 0.78749 0.77734 0.76329 0.75653 0.74207 0.72610 0.71928 693 nm 0.83057 0.81751 0.80235 0.79029 0.77913 0.76468 0.75417 0.74559 0.73236 694 nm 0.84067 0.83041 0.81674 0.80409 0.78959 0.77977 0.77171 0.75430 0.74347 695 nm 0.85438 0.84491 0.83224 0.81948 0.80731 0.79462 0.78425 0.77103 0.76048 696 nm 0.87009 0.85938 0.84873 0.83082 0.81966 0.80737 0.79485 0.78336 0.77542 697 nm 0.88250 0.87089 0.85528 0.84315 0.83042 0.82140 0.80550 0.79784 0.78385 698 nm 0.89514 0.88045 0.86759 0.85686 0.84831 0.83358 0.82316 0.81013 0.79985 699 nm 0.90298 0.89312 0.87890 0.86638 0.85667 0.84326 0.82821 0.82216 0.80856 700 nm 0.91588 0.90337 0.88566 0.87942 0.86508 0.85438 0.84473 0.83000 0.81662 701 nm 0.92416 0.91464 0.90406 0.88702 0.87977 0.86353 0.85174 0.84086 0.83206 702 nm 0.93556 0.92286 0.91033 0.90265 0.88861 0.87638 0.86469 0.85091 0.83958 703 nm 0.94464 0.92976 0.92086 0.90517 0.89383 0.88544 0.86948 0.86311 0.84956 704 nm 0.95172 0.94134 0.92452 0.91652 0.90713 0.89536 0.87968 0.86897 0.85622 705 nm 0.96445 0.94477 0.94112 0.92292 0.91835 0.90046 0.88922 0.87454 0.86843 706 nm 0.97045 0.95788 0.95020 0.93519 0.92430 0.91298 0.89947 0.88786 0.87275 707 nm 0.98165 0.96576 0.95652 0.94251 0.93266 0.92085 0.90612 0.89648 0.88468 708 nm 0.98706 0.97196 0.96089 0.95344 0.93654 0.92808 0.91656 0.90630 0.89525 709 nm 0.99556 0.97889 0.96765 0.95331 0.94638 0.93428 0.91999 0.91175 0.90195  10 nm 1.00000 0.98436 0.97267 0.95728 0.95293 0.93689 0.92688 0.91517 0.90614

TABLE 3B Normalized Excitation/Emission Spectrum of NIST SRM 2944 Glass (Excitation Range of 639 nm to 647 nm) Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Emission λ 639 nm 640 nm 641 nm 642 nm 643 nm 644 nm 645 nm 646 nm 647 nm 660 nm 0.27911 0.27185 0.26452 0.25901 0.25135 0.24785 0.23902 0.23594 0.23167 661 nm 0.28995 0.28094 0.27595 0.26975 0.26183 0.25660 0.25034 0.24434 0.23738 662 nm 0.30021 0.29278 0.28366 0.27893 0.27137 0.26506 0.25849 0.25475 0.24551 663 nm 0.31158 0.30306 0.29624 0.28923 0.28192 0.27477 0.26761 0.26381 0.25771 664 nm 0.32579 0.31660 0.30891 0.30162 0.29329 0.28622 0.27996 0.27318 0.26751 665 nm 0.33523 0.32804 0.31951 0.31145 0.30404 0.29706 0.28971 0.28405 0.27674 666 nm 0.34443 0.33741 0.33095 0.32289 0.31555 0.30954 0.30037 0.29415 0.28606 667 nm 0.35897 0.35202 0.34426 0.33462 0.32785 0.32013 0.31137 0.30462 0.29813 668 nm 0.37347 0.36475 0.35725 0.34954 0.34101 0.33435 0.32413 0.31842 0.30883 669 nm 0.38590 0.37578 0.36848 0.36081 0.35423 0.34506 0.33669 0.33021 0.31995 670 nm 0.39942 0.38957 0.38234 0.37419 0.36530 0.35769 0.34828 0.34083 0.33246 671 nm 0.41226 0.40227 0.39425 0.38722 0.37700 0.37099 0.35937 0.35261 0.34617 672 nm 0.42698 0.41667 0.40787 0.39921 0.39076 0.38205 0.37587 0.36751 0.36019 673 nm 0.43981 0.43263 0.42078 0.41488 0.40511 0.39550 0.38413 0.37933 0.36968 674 nm 0.45412 0.44475 0.43423 0.42555 0.41891 0.40664 0.40179 0.39040 0.38156 675 nm 0.46688 0.45568 0.44866 0.43969 0.43155 0.42118 0.41290 0.40209 0.39604 676 nm 0.48073 0.47073 0.46036 0.45261 0.44345 0.43448 0.42458 0.41554 0.40821 677 nm 0.49339 0.48261 0.47440 0.46501 0.45556 0.44665 0.43779 0.42705 0.41914 678 nm 0.50585 0.49479 0.48616 0.47395 0.46894 0.45722 0.44763 0.43920 0.43098 679 nm 0.51982 0.51266 0.50154 0.49310 0.48233 0.47278 0.46128 0.45399 0.44395 680 nm 0.53750 0.52403 0.51516 0.50484 0.49664 0.48659 0.47725 0.46932 0.45799 681 nm 0.54993 0.54309 0.52722 0.51938 0.50822 0.50052 0.49061 0.48152 0.47112 682 nm 0.56629 0.55587 0.54475 0.53432 0.52582 0.51478 0.50473 0.49179 0.48528 683 nm 0.58150 0.56910 0.55823 0.55040 0.54175 0.53082 0.51382 0.50954 0.49833 684 nm 0.59626 0.58549 0.57161 0.56348 0.55152 0.54292 0.53166 0.52173 0.51299 685 nm 0.60793 0.59802 0.58731 0.57827 0.56494 0.55536 0.54588 0.53733 0.52397 686 nm 0.62306 0.61432 0.59987 0.58847 0.58125 0.57004 0.55623 0.54756 0.53980 687 nm 0.63897 0.62686 0.61389 0.60637 0.59225 0.58169 0.57082 0.56042 0.55440 688 nm 0.65070 0.64051 0.62660 0.61937 0.60813 0.59850 0.58688 0.57622 0.56656 689 nm 0.66528 0.65593 0.64145 0.63173 0.62156 0.60885 0.59913 0.58936 0.57848 690 nm 0.67591 0.66659 0.65579 0.64355 0.63498 0.62411 0.61001 0.60088 0.59155 691 nm 0.69007 0.67921 0.67153 0.65932 0.64955 0.63466 0.62460 0.61504 0.60294 692 nm 0.70667 0.69526 0.68166 0.67403 0.66398 0.65158 0.63974 0.62803 0.61911 693 nm 0.72124 0.71108 0.69785 0.68725 0.67435 0.66574 0.65178 0.64059 0.63174 694 nm 0.73618 0.72511 0.71025 0.69935 0.69291 0.68093 0.66894 0.65427 0.64630 695 nm 0.74781 0.73408 0.72458 0.71131 0.70287 0.69274 0.68404 0.67117 0.65988 696 nm 0.76197 0.74705 0.73821 0.72851 0.71581 0.70501 0.69595 0.68463 0.67072 697 nm 0.77559 0.76219 0.75201 0.74229 0.72922 0.71381 0.70528 0.69469 0.68236 698 nm 0.78480 0.77821 0.76451 0.75169 0.73934 0.73148 0.71671 0.70809 0.69831 699 nm 0.79627 0.78192 0.77271 0.76445 0.74887 0.74191 0.73119 0.71864 0.70551 700 nm 0.80875 0.79373 0.78544 0.77658 0.75904 0.75085 0.73887 0.72835 0.71694 701 nm 0.82209 0.80501 0.79439 0.78660 0.77305 0.75991 0.75274 0.74043 0.73168 702 nm 0.82774 0.81885 0.80382 0.79314 0.78494 0.76795 0.76162 0.75244 0.73873 703 nm 0.83419 0.82483 0.81362 0.80471 0.79361 0.78072 0.77200 0.75994 0.74859 704 nm 0.85007 0.83739 0.82417 0.81290 0.80216 0.78760 0.77658 0.77141 0.75671 705 nm 0.85479 0.84240 0.83616 0.82402 0.80819 0.79908 0.78787 0.77910 0.76791 706 nm 0.86330 0.85349 0.84185 0.82907 0.81821 0.80705 0.79720 0.79097 0.77680 707 nm 0.87533 0.85838 0.85322 0.84090 0.82425 0.82040 0.80514 0.79461 0.78601 708 nm 0.87902 0.87176 0.85697 0.84603 0.83478 0.82536 0.81204 0.80294 0.79474 709 nm 0.88992 0.87785 0.86414 0.85678 0.84718 0.83483 0.82128 0.81027 0.79945 710 nm 0.89614 0.88186 0.87009 0.86187 0.85009 0.83553 0.82659 0.82019 0.80709

TABLE 3C Normalized Excitation/Emission Spectrum of NIST SRM 2944 Glass (Excitation Range of 648 nm to 655 nm) Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Excitation λ Emission λ 648 nm 649 nm 650 nm 651 nm 652 nm 653 nm 654 nm 655 nm 660 nm 0.22307 0.21862 0.21234 0.20707 0.20283 0.19818 0.19434 0.19945 661 nm 0.23246 0.22495 0.22051 0.21522 0.21042 0.20606 0.20101 0.19704 662 nm 0.24082 0.23491 0.22850 0.22278 0.21853 0.21427 0.20871 0.20469 663 nm 0.25162 0.24477 0.23645 0.23321 0.22687 0.22342 0.21649 0.21101 664 nm 0.26040 0.25317 0.24677 0.24088 0.23597 0.23001 0.22623 0.21969 665 nm 0.26949 0.26390 0.25812 0.25110 0.24596 0.23964 0.23430 0.22715 666 nm 0.28044 0.27314 0.26748 0.25994 0.25424 0.24853 0.24207 0.23773 667 nm 0.29144 0.28471 0.27705 0.27033 0.26524 0.25781 0.25273 0.24673 668 nm 0.30424 0.29720 0.28912 0.28144 0.27547 0.26940 0.26398 0.25484 669 nm 0.31480 0.30627 0.29854 0.29071 0.28693 0.28079 0.27288 0.26618 670 nm 0.32499 0.31901 0.31044 0.30256 0.29579 0.29054 0.28507 0.27643 671 nm 0.33695 0.33028 0.32168 0.31329 0.30769 0.29974 0.29415 0.28682 672 nm 0.35154 0.34241 0.33350 0.32585 0.31779 0.31141 0.30409 0.29844 673 nm 0.36206 0.35317 0.34607 0.33680 0.32910 0.32296 0.31487 0.30683 674 nm 0.37249 0.36744 0.35645 0.34757 0.34151 0.33411 0.32546 0.31931 675 nm 0.38513 0.37680 0.37132 0.36100 0.35348 0.34651 0.33660 0.33213 676 nm 0.39830 0.38919 0.38056 0.37358 0.36698 0.35720 0.34857 0.33951 677 nm 0.40869 0.40122 0.39366 0.38278 0.37662 0.36828 0.36053 0.35445 678 nm 0.42164 0.41460 0.40237 0.39651 0.38763 0.37992 0.37141 0.36531 679 nm 0.43349 0.42601 0.41659 0.40618 0.39905 0.39172 0.38240 0.37497 680 nm 0.45032 0.44037 0.43041 0.42288 0.41332 0.40584 0.39514 0.38954 681 nm 0.46247 0.45195 0.44170 0.43335 0.42404 0.41838 0.40698 0.39738 682 nm 0.47560 0.46757 0.45571 0.44799 0.43733 0.42737 0.42113 0.41283 683 nm 0.48577 0.48138 0.46818 0.46202 0.45340 0.44252 0.43443 0.42419 684 nm 0.50254 0.49332 0.48344 0.47429 0.46366 0.45632 0.44797 0.43761 685 nm 0.51655 0.50645 0.49770 0.48468 0.47363 0.46564 0.45579 0.45023 686 nm 0.52648 0.51785 0.50762 0.49781 0.48867 0.48044 0.46849 0.45994 687 nm 0.54333 0.53133 0.52121 0.50969 0.50280 0.49216 0.48218 0.47060 688 nm 0.55721 0.54386 0.53374 0.52499 0.51500 0.50429 0.49431 0.48410 689 nm 0.56593 0.55658 0.54389 0.53722 0.52538 0.51817 0.50748 0.49488 690 nm 0.58141 0.57162 0.55913 0.55088 0.53814 0.53011 0.51971 0.50912 691 nm 0.59442 0.58090 0.57177 0.56071 0.55108 0.54204 0.53196 0.52437 692 nm 0.60802 0.59742 0.58562 0.57557 0.56810 0.55619 0.54572 0.53520 693 nm 0.61806 0.61048 0.60156 0.58885 0.57871 0.56818 0.56005 0.55053 694 nm 0.63058 0.62611 0.60978 0.60223 0.59056 0.58141 0.57157 0.56200 695 nm 0.64782 0.63917 0.62542 0.61524 0.60570 0.59401 0.58392 0.57225 696 nm 0.66502 0.65048 0.64032 0.62578 0.61605 0.60660 0.59913 0.58509 697 nm 0.67196 0.66391 0.65115 0.64087 0.63057 0.61819 0.60895 0.59958 698 nm 0.68370 0.67084 0.66268 0.65501 0.64005 0.63120 0.62074 0.60900 699 nm 0.69510 0.68551 0.67157 0.66240 0.65280 0.64155 0.62950 0.62099 700 nm 0.70688 0.69564 0.68446 0.67570 0.66249 0.65235 0.63999 0.62854 701 nm 0.71596 0.70828 0.69418 0.68431 0.67283 0.66207 0.64923 0.64099 702 nm 0.72934 0.71764 0.70616 0.69496 0.68405 0.67309 0.66337 0.65407 703 nm 0.73582 0.72721 0.71421 0.70465 0.69440 0.68092 0.67209 0.66131 704 nm 0.74703 0.73430 0.72530 0.71079 0.70244 0.69213 0.68112 0.67269 705 nm 0.75439 0.74683 0.73679 0.72472 0.71410 0.70194 0.69075 0.67711 706 nm 0.76728 0.75756 0.74230 0.72972 0.72297 0.71639 0.69829 0.69141 707 nm 0.77383 0.76340 0.75084 0.74204 0.73260 0.71983 0.71077 0.69931 708 nm 0.78383 0.77095 0.76037 0.75105 0.73926 0.72877 0.71753 0.70840 709 nm 0.79008 0.78214 0.76971 0.75695 0.74783 0.73712 0.72513 0.71338 710 nm 0.79852 0.78818 0.77288 0.76500 0.75695 0.74266 0.73116 0.72153

TABLE 4 Relative Absorption of Alexa Fluor ® 647 vs. Excitation Wavelength Excitation Wavelength AF 647 Relative (nm) Absorption 630 0.5403 631 0.5666 632 0.5917 633 0.6202 634 0.6501 635 0.6780 636 0.7052 637 0.7364 638 0.7706 639 0.8041 640 0.8279 641 0.8537 642 0.8796 643 0.9080 644 0.9325 645 0.9504 646 0.9666 647 0.9826 648 0.9920 649 0.9977 650 1.0000 651 0.9956 652 0.9905 653 0.9747 654 0.9590 655 0.9391

TABLE 5 Relative Emission Intensity of Alexa Fluor ® 647 vs. Wavelength Emission Wavelength Relative Emission nm Intensity 660 0.7259 661 0.7660 662 0.8055 663 0.8477 664 0.8856 665 0.9075 666 0.9320 667 0.9507 668 0.9738 669 0.9841 670 0.9973 671 1.0000 672 0.9928 673 0.9827 674 0.9688 675 0.9522 676 0.9390 677 0.9057 678 0.8844 679 0.8615 680 0.8339 681 0.8042 682 0.7709 683 0.7475 684 0.7092 685 0.6830 686 0.6567 687 0.6199 688 0.5930 689 0.5717 690 0.5372 691 0.5095 692 0.4887 693 0.4652 694 0.4451 695 0.4267 696 0.4064 697 0.3899 698 0.3731 699 0.3564 700 0.3406 701 0.3303 702 0.3180 703 0.3064 704 0.2973 705 0.2845 706 0.2749 707 0.2693 708 0.2625 709 0.2528 710 0.2494

TABLE 6 Relative Absorption of Alexa Fluor ® 635 vs. Excitation Wavelength Excitation Wavelength AF 635 Relative (nm) Absorption 300 0.446957202 301 0.396653342 302 0.343918215 303 0.295014831 304 0.248871208 305 0.210934787 306 0.179785525 307 0.154627416 308 0.133971426 309 0.119256131 310 0.105066014 311 0.092018933 312 0.08507731 313 0.07738499 314 0.070948979 315 0.066119397 316 0.061795427 317 0.056687809 318 0.052547137 319 0.049170548 320 0.045328507 321 0.04315571 322 0.040128211 323 0.038543407 324 0.038780253 325 0.038624759 326 0.036226444 327 0.038645354 328 0.037966741 329 0.03680311 330 0.037255176 331 0.03745083 332 0.036782515 333 0.037184122 334 0.037286068 335 0.037224283 336 0.037347854 337 0.037430235 338 0.037647515 339 0.038295235 340 0.038718467 341 0.040220889 342 0.041395847 343 0.042836484 344 0.043783865 345 0.045607573 346 0.04683196 347 0.048283924 348 0.049325013 349 0.050344477 350 0.051013822 351 0.052280429 352 0.053093941 353 0.054082512 354 0.055019595 355 0.056027732 356 0.057377749 357 0.058983148 358 0.060467034 359 0.061568879 360 0.063565587 361 0.06554273 362 0.067015289 363 0.068705128 364 0.070186955 365 0.071350586 366 0.072462729 367 0.073389514 368 0.073986776 369 0.074636556 370 0.07504846 371 0.075469633 372 0.07612868 373 0.076315067 374 0.075985544 375 0.076880406 376 0.076726972 377 0.07677846 378 0.077796894 379 0.078806061 380 0.079362132 381 0.081236299 382 0.082286655 383 0.083790108 384 0.085303857 385 0.086354214 386 0.086777446 387 0.086087506 388 0.085169988 389 0.083501774 390 0.081287787 391 0.078620704 392 0.075923758 393 0.072740764 394 0.069394039 395 0.065687926 396 0.062051838 397 0.058406481 398 0.055009297 399 0.05188809 400 0.048953269 401 0.046184239 402 0.044638567 403 0.042949758 404 0.042712913 405 0.042549181 406 0.043176305 407 0.044144281 408 0.045503567 409 0.052867393 410 0.048532096 411 0.049653507 412 0.051084875 413 0.051868524 414 0.052475054 415 0.052331917 416 0.051981798 417 0.051003524 418 0.049582453 419 0.047851424 420 0.04626662 421 0.044124716 422 0.041313467 423 0.039376485 424 0.036791783 425 0.034980432 426 0.032899284 427 0.031241367 428 0.029399123 429 0.027843153 430 0.027060535 431 0.026195535 432 0.024899065 433 0.024362559 434 0.023754999 435 0.023806488 436 0.022746863 437 0.022489422 438 0.021737696 439 0.021623393 440 0.02098494 441 0.020500952 442 0.02033722 443 0.020048887 444 0.019687441 445 0.019410435 446 0.018935715 447 0.018514542 448 0.018081012 449 0.017495078 450 0.01718512 451 0.017031685 452 0.016351013 453 0.015918513 454 0.015301686 455 0.015095733 456 0.014672501 457 0.014488174 458 0.014127757 459 0.013766311 460 0.013405894 461 0.013417222 462 0.012995019 463 0.012892043 464 0.012686091 465 0.012531627 466 0.012098097 467 0.011984823 468 0.011593514 469 0.011378293 470 0.01108996 471 0.010760436 472 0.010460776 473 0.010513294 474 0.010307341 475 0.010163175 476 0.010060198 477 0.010019008 478 0.009782163 479 0.009524722 480 0.009410419 481 0.009380556 482 0.00910252 483 0.008936728 484 0.008947026 485 0.00884405 486 0.008721508 487 0.008752401 488 0.008833752 489 0.008927461 490 0.009071627 491 0.009349663 492 0.009452639 493 0.009668889 494 0.009957222 495 0.010213633 496 0.010285716 497 0.010523591 498 0.010862383 499 0.011192936 500 0.01126502 501 0.011512162 502 0.011995121 503 0.012314347 504 0.012850853 505 0.013324543 506 0.013818829 507 0.014385198 508 0.014941269 509 0.015310953 510 0.016062679 511 0.016670239 512 0.01765881 513 0.01830859 514 0.019122102 515 0.020306327 516 0.021489524 517 0.022808648 518 0.024063928 519 0.025599303 520 0.027102755 521 0.028935731 522 0.030593647 523 0.032591385 524 0.034639581 525 0.036410771 526 0.038831741 527 0.040675014 528 0.042887972 529 0.045257454 530 0.047501305 531 0.049591721 532 0.05193031 533 0.054257571 534 0.056286202 535 0.05850019 536 0.060364058 537 0.062247492 538 0.06398779 539 0.065666301 540 0.066943206 541 0.068456956 542 0.069580426 543 0.070702866 544 0.072215586 545 0.073399812 546 0.074913562 547 0.076458204 548 0.078312805 549 0.079991317 550 0.082370066 551 0.085067012 552 0.087806178 553 0.091400047 554 0.095117486 555 0.099360105 556 0.104055818 557 0.109421907 558 0.115342007 559 0.121850101 560 0.128842183 561 0.136432556 562 0.144618132 563 0.153289756 564 0.162844915 565 0.172514377 566 0.18313225 567 0.193594629 568 0.204994091 569 0.216249387 570 0.228512819 571 0.240241805 572 0.25253716 573 0.264133307 574 0.275821102 575 0.287219535 576 0.298712705 577 0.309184352 578 0.319399588 579 0.328667444 580 0.3370703 581 0.344207578 582 0.350303767 583 0.354978886 584 0.358552159 585 0.359890849 586 0.360209045 587 0.358386367 588 0.355236326 589 0.350581803 590 0.345050953 591 0.338203037 592 0.330666211 593 0.322880183 594 0.315260976 595 0.307969233 596 0.301574413 597 0.296158896 598 0.292213879 599 0.289752749 600 0.289135921 601 0.289979296 602 0.292976933 603 0.297548045 604 0.304026276 605 0.312582566 606 0.323190141 607 0.336041568 608 0.350643589 609 0.367674818 610 0.386478267 611 0.407578084 612 0.430449092 613 0.455286945 614 0.48257666 615 0.510771536 616 0.541385322 617 0.573123608 618 0.607094417 619 0.641138339 620 0.677139839 621 0.7121816 622 0.7481831 623 0.78335873 624 0.818423146 625 0.852023241 626 0.883297105 627 0.911862695 628 0.937339 629 0.959623043 630 0.977274189 631 0.989372859 632 0.998094941 633 1 634 0.996438054 635 0.98686127 636 0.97186794 637 0.951200622 638 0.924982889 639 0.893842894 640 0.858419091 641 0.820461045 642 0.778570338 643 0.734971257 644 0.6888472 645 0.643063994 646 0.595664062 647 0.549468951 648 0.504469394 649 0.461135991 650 0.419945523 651 0.379960905 652 0.343331251 653 0.308186513 654 0.276006459 655 0.245730435 656 0.218813494 657 0.193428838 658 0.171083008 659 0.150746244 660 0.132704819 661 0.116547858 662 0.102007622 663 0.089783321 664 0.078539353 665 0.068292194 666 0.059540249 667 0.052105369 668 0.04514418 669 0.039252913 670 0.034093807 671 0.029614344 672 0.025949422 673 0.02249869 674 0.019667875 675 0.017217042 676 0.015260495 677 0.01325246 678 0.011459645 679 0.01014155 680 0.009071627 681 0.007897699 682 0.006847342 683 0.005826848 684 0.005076152 685 0.004405777 686 0.003849705 687 0.00357167 688 0.002840539 689 0.002572801 690 0.002161926 691 0.001851968 692 0.001502879 693 0.001399902 694 0.00119292 695 0.000894289 696 0.000606986 697 0.00050298 698 0.000420599 699 0.000400004 700 6.01824E−05 701 0

TABLE 7 Relative Emission of Alexa Fluor ® 635 vs. Excitation Wavelength Excitation Wavelength AF 635 Relative (nm) Emission 604 0 605 0.027431 606 0.017998 607 0.019215 608 0.02091 609 0.023258 610 0.027127 611 0.032561 612 0.038647 613 0.043516 614 0.050559 615 0.058949 616 0.067991 617 0.080033 618 0.09151 619 0.1029 620 0.123549 621 0.139112 622 0.158848 623 0.179716 624 0.210278 625 0.2371 626 0.267661 627 0.303874 628 0.342476 629 0.377472 630 0.424423 631 0.465983 632 0.504848 633 0.556275 634 0.597575 635 0.653437 636 0.6943 637 0.741251 638 0.785245 639 0.836238 640 0.865495 641 0.901883 642 0.932834 643 0.954136 644 0.979742 645 0.989957 646 0.999566 647 0.999695 648 1 649 0.996131 650 0.978916 651 0.970612 652 0.950181 653 0.925314 654 0.897187 655 0.8698 656 0.834891 657 0.802113 658 0.766769 659 0.734991 660 0.704212 661 0.676042 662 0.635264 663 0.602313 664 0.5681 665 0.541495 666 0.51002 667 0.480893 668 0.454419 669 0.428379 670 0.402556 671 0.378646 672 0.357867 673 0.34013 674 0.318828 675 0.302047 676 0.285789 677 0.26753 678 0.251533 679 0.242272 680 0.22684 681 0.218666 682 0.208494 683 0.195713 684 0.187975 685 0.181454 686 0.172065 687 0.163109 688 0.157284 689 0.150806 690 0.143981 691 0.139417 692 0.134678 693 0.131461 694 0.127027 695 0.123636 696 0.121288 697 0.119202 698 0.117637 699 0.114681 700 0.114072 701 0.110768 702 0.107812 703 0.107551 704 0.106508 705 0.105378 706 0.103986 707 0.101465 708 0.099683 709 0.099074 710 0.098596 711 0.097987 712 0.09577 713 0.094422 714 0.094118 715 0.090597 716 0.087076 717 0.083772 718 0.085076 719 0.082381 720 0.081294 721 0.078207 722 0.075294 723 0.074208 724 0.070556 725 0.069165 726 0.067513 727 0.063253 728 0.058731 729 0.058949 730 0.056384 731 0.055297 732 0.052341 733 0.049385 734 0.046211 735 0.045081 736 0.044864 737 0.040082 738 0.039864 739 0.037778 740 0.03643 741 0.034778 742 0.032952 743 0.029996 744 0.029474 745 0.028605 746 0.025736 747 0.025301 748 0.023649 749 0.023867 750 0.021475 751 0.022388 752 0.019389 753 0.019389 754 0.018215 755 0.016302 756 0.016694 757 0.016346 758 0.015694 759 0.015215 760 0.014737 761 0.012911 762 0.012129 763 0.012042 764 0.012737 765 0.011172 766 0.010999 767 0.009868 768 0.009912 769 0.010607 770 0.010477 771 0.008695 772 0.008868 773 0.008868 774 0.008129 775 0.008955 776 0 

We claim:
 1. A method of normalizing a first diagnostic result of a subordinate clinical diagnostic analyzer to a second diagnostic result of a master clinical diagnostic analyzer comprising the steps of obtaining a normalized excitation intensity spectrum of the master clinical diagnostic analyzer, obtaining a normalized excitation intensity spectrum of the subordinate clinical diagnostic analyzer, obtaining a normalized responsivity intensity spectrum of the master clinical diagnostic analyzer, obtaining a normalized responsivity intensity spectrum of the subordinate clinical diagnostic analyzer, obtaining a normalized excitation/emission spectrum of a solid inorganic photostable fluorophore calibration target, reading the solid inorganic photostable fluorophore calibration target in the master clinical diagnostic analyzer thereby obtaining a first response value, reading the solid inorganic photostable fluorophore calibration target in the subordinate clinical diagnostic analyzer thereby obtaining a second response value, determining the gain ratio of the master clinical diagnostic analyzer to the subordinate clinical diagnostic analyzer based upon the two above obtained response values, determining a multiplicative normalization factor between a normalized subordinate clinical diagnostic analyzer and the master clinical diagnostic analyzer, determining the relative adsorption/emission spectrum of a first fluorescently labeled dye whereas the first fluorescently labeled dye is a diagnostic assay component, obtaining a first diagnostic result from a specific patient specimen or sample incorporating the first fluorescently labeled dye using the normalized subordinate clinical diagnostic analyzer, and modifying the first diagnostic result by the multiplicative normalization factor to obtain a second diagnostic result wherein the second diagnostic result is a normalized approximation to a diagnostic result which would be obtained by analyzing the specific patient specimen or sample on the master clinical diagnostic analyzer.
 2. A method to re-normalize a subordinate clinical diagnostic analyzer assay result as compared to a master clinical diagnostic analyzer assay result comprising the steps of normalizing the subordinate clinical diagnostic analyzer as claimed in claim 1, determining a relative adsorption/intensity spectrum of a second fluorescently labeled dye whereas the second fluorescently labeled dye is a diagnostic assay component, determining a re-normalization multiplicative factor between a subordinate clinical diagnostic analyzer and a master clinical diagnostic analyzer, obtaining a first diagnostic result from a specific patient specimen or sample incorporating the second fluorescently labeled dye using the normalized subordinate clinical diagnostic analyzer, and modifying the first diagnostic result by the re-normalization factor to obtain a second diagnostic result wherein the second diagnostic result is a normalized approximation to a diagnostic result which would be obtained by analyzing the specific patient specimen or sample on the master clinical diagnostic analyzer.
 3. A method as claimed in claim 1, wherein the solid inorganic photostable fluorophore is a phosphate matrix glass.
 4. A method as claimed in claim 2, wherein the phosphate matrix glass is a bismuth-doped phosphate glass.
 5. A method as claimed in claim 2, wherein the phosphate matrix glass is a copper-doped phosphate glass.
 6. A method as claimed in claim 1, wherein the modification of the first diagnostic result by the multiplicative normalization factor to obtain the second diagnostic result is accomplished by numerical multiplication.
 7. A method as claimed in claim 1, wherein the modification of the first diagnostic result by the multiplicative normalization factor to obtain the second diagnostic result is accomplished by using a linear calibration curve having a differing slope.
 8. A method as claimed in claim 2, wherein the modification of the first diagnostic result by the multiplicative re-normalization factor to obtain the second diagnostic result is accomplished by numerical multiplication.
 9. A method as claimed in claim 2, wherein the modification of the first diagnostic result by the multiplicative re-normalization factor to obtain the second diagnostic result is accomplished by using a linear calibration curve having a differing slope.
 10. A method as claimed in claim 1, wherein the modification of the first diagnostic result by the multiplicative normalization factor to obtain the second diagnostic result in the case of a non-linear calibration curve is accomplished by numerical multiplication. 